Ondol is a Korean under-floor heating system.

GAPS is a hot water heating mat manufacturer, main products is portable ONDOL mats called Warm water circulation mat, Heated mattress pad, Cooling mattress pad and etc. GAPS provides neither drive noise and nor vibration as it has no motor pump for hot water and PCM cool pad. It provides excellent performance with high efficiency and ultra low noise (10dB or less) helping you to have good sleep.